I think it's a great idea. But I think it would be the smartest thing to do if it lasted more than one night. I guess it would make more people come. I don't think a lot would spend the money to go to England for one night (if talking about BBQ), and certainly not on a trip to Spain. Plus if it was in a pub, it wouldn't be that cosy, people would get too drunk too fast, and what about those who aren't allowed to enter the pub/have alcohol due to age limit? I'm not really sure about the British rules, but aren't they rather strict?
About people getting drunk. Yes it's funny (at least I think so), but whether the whole thing will be good, also has something to do with people's way of drinking. Some people simply can't control it, some people can. I think it would be a shame only to meet the people from KKW when drunk (or being drunk most of the time). People often say a lot of stupid things when the drink alcohol.